New Lead Acid Batteries; Charge & Monitor Upgrade?

[peteco]

My batteries (Duracell deep cycles from Sam's Club) are not bulging and from all outward appearances look new when I wipe them down. I haven't really paid attention to the plates. No reason to until now, but before our next trip, I'll probably be replacing them. If they look bulged or sulfated, then I guess a replacement for my Tripp Lite will be next.

Problem then, is do I start the ball rolling down hill and add two battle born lithiums, a DC to DC charger, and additional solar? Voila, $3500 later.

Same thoughts here. What would possibly push me to a lithium upgrade would be if I change to a compressor fridge, though you and others have made it without lithium. But fridge plus electrical upgrade would push to $5k+ range. Not sure that makes sense on a 2006 rig, though I do plan to keep it until the wheels fall off (either the vehicle's or mine).

 

[Knit]

A year or so ago I was looking into Battleborns for my 2013 Roadtrek RS that has a Tripp-Lite RV750ULHW

I asked Tripp-Lite support about its charging and they said:

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing.

Battleborn said this would not work:

The Tripp-Lite inverter charger is not compatible im looking at the manual now and it doesn’t list the float voltage or the bulk/absorption.

The bulk/absorption needs to be set to 14.4V-14.6V, float voltage needs to be set to 13.6V and the equalization needs to be turned off.

 

[rowiebowie]

A year or so ago I was looking into Battleborns for my 2013 Roadtrek RS that has a Tripp-Lite RV750ULHW

I asked Tripp-Lite support about its charging and they said:

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing.

Battleborn said this would not work:

The Tripp-Lite inverter charger is not compatible im looking at the manual now and it doesn’t list the float voltage or the bulk/absorption.

The bulk/absorption needs to be set to 14.4V-14.6V, float voltage needs to be set to 13.6V and the equalization needs to be turned off.

Thanks for the post. What did Battleborn suggest in the way of chargers or charge features to look for. For instance, is it enough to merely get a charger with a "lithium" setting? Did they suggest a DC to DC charger between your engine alternator and their batteries? This is what Renogy suggested to me, but I've not made the decision to go lithium due to battery cost and all the upgraded inverter and charger costs.

 

[booster]

Thanks for the post. What did Battleborn suggest in the way of chargers or charge features to look for. For instance, is it enough to merely get a charger with a "lithium" setting? Did they suggest a DC to DC charger between your engine alternator and their batteries? This is what Renogy suggested to me, but I've not made the decision to go lithium due to battery cost and all the upgraded inverter and charger costs.

If you look at their site, they are selling the Progressive Dynamics lithium charger, which if it hasn't changed is just a 14.6v fixed output charger with no float. Current thinking by most lithium system charging experts seems to have severely reduced the charging voltage to the 13.8v range and use a full cutoff, auto recharge when needed. Holding at 14.6v is being said to be quite bad for lithium batteries. Very contradictory to some of the things Battleborn has told customers. IMO, this is not really surprising as their claims and information on the website have also been all over the place with some major misleading comparisons to other batteries.

 

[markopolo-ClassB]

A year or so ago I was looking into Battleborns for my 2013 Roadtrek RS that has a Tripp-Lite RV750ULHW

I asked Tripp-Lite support about its charging and they said:

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing.

Battleborn said this would not work:

The Tripp-Lite inverter charger is not compatible im looking at the manual now and it doesn’t list the float voltage or the bulk/absorption.

The bulk/absorption needs to be set to 14.4V-14.6V, float voltage needs to be set to 13.6V and the equalization needs to be turned off.

Basically, you were brushed off by Tripp Lite if that was the answer they provided. I'm assuming that you asked about specifics related to your particular Tripp Lite model.


That answer appears to have been directly copied from a 2007 book - Off the Grid By LaMar Alexander - https://books.google.ca/books?id=p57ZAgAAQBAJ&pg=PA142&lpg=PA142#v=onepage&q&f=false


It's a somewhat dated, generalized description of lead acid battery charging.


From what Tripp Lite RV series users have measured and reported we know that bulk and absorption on those units is around 14.4V and float is around 13.5V. There are worse ways to charge lithium batteries than that.

 

[markopolo-ClassB]

A fairly low cost way to get pretty good charging for lead acid batteries would be to use a charger like the 40 amp KISAE Technology AC 1240 Abso Charger and the BTS-10K Battery Temperature Sensor. Cost would be around $320 plus some additional wiring. It also has a programmable lithium charging profile so t's somewhat future proofed.

Transition to float can be set to occur at 2A and it would have temperature compensation.

It looks like you can turn off the charger section - DIP switch A2 - on the 750 model so you could leave it in place and likely still use the inverter section.

It's all about space in a B van so I don't know if both units would fit in that area though.

 

[booster]

A fairly low cost way to get pretty good charging for lead acid batteries would be to use a charger like the 40 amp KISAE Technology AC 1240 Abso Charger and the BTS-10K Battery Temperature Sensor. Cost would be around $320 plus some additional wiring. It also has a programmable lithium charging profile so t's somewhat future proofed.

Transition to float can be set to occur at 2A and it would have temperature compensation.

It looks like you can turn off the charger section - DIP switch A2 - on the 750 model so you could leave it in place and likely still use the inverter section.

It's all about space in a B van so I don't know if both units would fit in that area though.

I just took a look at the Kisae manual, which I hadn't done in quite while, and they do have a lithium profile that shuts off the charging when complete and then rebulks when needed after discharging. Looks like at least some of the parameters like charge voltage are settable, and hopefully the rebulk voltage, which makes it much more likable for lithium in a small battery bank and small charger setup. Using the the full shutoff on a small system, while good for the batteries, does take away the ability to run the van off of the charger or solar once the batteries are charged, so you have the possibility of having fairly low battery SOC at any given time depending on where you are in the charge/discharge cycle. Huge battery banks mostly mask the issue as they have so much capacity, unless the use is also very large like with AC or other very high draw stuff.


As always :whistling: I would remind that the Kisae, like most chargers that can use amps to transition to float, does the amp measuring internally and will be fooled by any loads running in the van. We learned this the hard way over time when we had the Blue Sea charger which also measured internally. A 2 amp setting is very low for an internally measured amp transition, IMO, based on what we saw in our van. We had .4-.5amps of load from detectors and such and originally had a separator that would close when on shore charge and add another 1.4amps for the coil of the separator plus whatever the van electronics and starting battery were taking putting us over 2 amps all the time until we put a disconnect on the separator. Even with the separator out of the picture the TV or ceiling vent fan would put us over the 2 amps and lock the charger in absorption until it timed out. Catch 22 was if you set the timer long enough to get the batteries full at 6-8 hours, you could stay in absorption for that long on full batteries on a hot day that you had the fan on continuously. The solution is mostly not very good as you turn up the transition amps to a best guess of what you load will be and then make sure you have that load when charging and not more or less. Another possibility is learning about how long it takes to get the batteries full and then shutting off all the loads for 5-10 minutes to let the charger see the lower amps and go to float, then turn the loads back on and the charger will stay in float with them on. The Blue Sea had three independently settable banks so I was able to make a relay setup to isolate the van loads from the batteries, but it is the only charger I know of that you can do that to. Our current Magnum MS2000 measures the transition amps at the batteries with a shunt so does not have the issue, but it is also nearly 10X the cost of the Kisae (including the remote, BMK monitor, shunt).

 

[markopolo-ClassB]

All good points from Booster :thumbup:

On the Kisae 40A, the Absorption to Float can be set to 2A or 4A or 8A.

With the Samlex in my Class A, I think I ended up going with 4A for the reasons Booster mentioned.

On the Kisae 40A, if already plugged in and charged, float exit is triggered when voltage dips to 12.5V so it would take a fairly large load (depending on battery bank size) to force it back to Bulk or Absorption.

On the Samlex EVO, the programmable range for automatic float exit is between 10V to 13V.

You could put the Kisae into Power Supply mode as well as a work around.

 

[peteco]

Charging update.

I still have the Tripplite set on 11 amp charge. I hooked up to 120v to charge the batteries. The Tripplite slowly got the charging to absorption: 14.4v, 5.5 amps into the two 6v house batteries; 14.4 v, 2.5 amps into chassis battery.

I was surprised that the charger was still in absorption after 3 hours: 14.4v, 4.8 amps into the two 6v house batteries; 14.4 v, 0.5 amps into chassis battery. I realized I had never checked the setup long-term with the separator connecting the batteries at the 11 amp Tripplite setting. On the 45 amp setting the Tripplite had only stayed in absorption for a few minutes.

I then put power to the separator to disconnect the chassis battery. The charger dropped to float within a few seconds. The Tripplite stayed in float even after reconnecting the chassis battery. I don’t understand why this happened.

So with the chassis batteries now still connected I then disconnected 120v and reconnected. The Tripplite went back to absorption. The 6v bank charge went to 5 amps and the chassis battery went to 2.5 amps. Not sure why the chassis batteries were now back to taking 2.5 amps instead of 0.5 amp where it had just been.

So I disconnected the chassis battery again. Then I disconnected and reconnected 120v. The Tripplite went to absorb for about 2 minutes, then dropped to float. So the chassis battery needs to be connected in for the Tripplite to stay in absorption. Again, not sure why.

I need to do a longer term check tomorrow as I did not want to leave the Tripplite hooked up overnight and possibly overcharge. The 11 amp setting definitely behaves different, and for the better, than the 45 amp setting. I just hope the Tripplite eventually drops to float. I am pretty sure it does as we went camping a few weeks ago and the voltmeter showed the batteries in float when I checked them after being plugged in for a few hours. This was also after the vehicle had been driven 2 hours so the chassis battery was near full, which may be a factor in how the charging occurs???

I am hoping that for maintenance purpose it may be that having a timer turn the Tripplite on for a few hours each day will work.

I am still working toward a small solar setup to keep the batteries at full charge as well. And I just purchased a Trimetric TM-2030-RV to monitor the system.

 

[booster]

Charging update.

I still have the Tripplite set on 11 amp charge. I hooked up to 120v to charge the batteries. The Tripplite slowly got the charging to absorption: 14.4v, 5.5 amps into the two 6v house batteries; 14.4 v, 2.5 amps into chassis battery.

I was surprised that the charger was still in absorption after 3 hours: 14.4v, 4.8 amps into the two 6v house batteries; 14.4 v, 0.5 amps into chassis battery. I realized I had never checked the setup long-term with the separator connecting the batteries at the 11 amp Tripplite setting. On the 45 amp setting the Tripplite had only stayed in absorption for a few minutes.

I then put power to the separator to disconnect the chassis battery. The charger dropped to float within a few seconds. The Tripplite stayed in float even after reconnecting the chassis battery. I don’t understand why this happened.

So with the chassis batteries now still connected I then disconnected 120v and reconnected. The Tripplite went back to absorption. The 6v bank charge went to 5 amps and the chassis battery went to 2.5 amps. Not sure why the chassis batteries were now back to taking 2.5 amps instead of 0.5 amp where it had just been.

So I disconnected the chassis battery again. Then I disconnected and reconnected 120v. The Tripplite went to absorb for about 2 minutes, then dropped to float. So the chassis battery needs to be connected in for the Tripplite to stay in absorption. Again, not sure why.

I need to do a longer term check tomorrow as I did not want to leave the Tripplite hooked up overnight and possibly overcharge. The 11 amp setting definitely behaves different, and for the better, than the 45 amp setting. I just hope the Tripplite eventually drops to float. I am pretty sure it does as we went camping a few weeks ago and the voltmeter showed the batteries in float when I checked them after being plugged in for a few hours. This was also after the vehicle had been driven 2 hours so the chassis battery was near full, which may be a factor in how the charging occurs???

I am hoping that for maintenance purpose it may be that having a timer turn the Tripplite on for a few hours each day will work.

I am still working toward a small solar setup to keep the batteries at full charge as well. And I just purchased a Trimetric TM-2030-RV to monitor the system.

It appears that the Tripplite is tripping at a lower amperage in the 11 amp mode, probably around the 5.5amps you are seeing to the coach in absorption.


I would guess the chassis battery was only taking the .5 amps while in float? so when back in absorption it would go back to the 2.5 amps due to higher voltage.